Telephone-exchange system.



F. N. REEvEs.

TELEPHONE EXCHANGE SYSTEM..

APPLICATION FILED NOV. 13.!916. L25,% Patented Jan.'8,1918.

2 SHEETS-SHEET 1- lm/en far.-

F.'N. REEVES. TELEPHONE EXCHANGE SYSTEM.

APPLlCATlON FILED NOV- I3, 1916- Patented Jan. 8, 1918.

2 SHEETS-SHEET 2.

In yen for: FfllI/f Reeves.-

maaaam it FRANK N. REEVES, OF NEVJARK, N EW PANY, INCORPORATED, 0F NEVI YORK, N.

JERSEY, ASSIGNOF. T0 WESTERN ELECTRIC. COM- Y., A CORPORATION OF NEW YORK.

TELEPHONE-EXCHANGE SYSTEM.

Specification of Letters Patent.

Patented Jan. 8, 1918.

Application filed November 13, 1916. Serial No. 13152 14.

T 0 all whom it may concern:

Be it known that I, FRANK N. REEVES, a citizen of the United States, residing at Newark, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in T elephone-EX- change Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone exchange systems and relates to allotters for determining the order in which certain pieces of apparatus shall be operated.

The object of this invention is the provis on of means whereby an automatic switch may be instantly allotted for service upon the seizure of a previously allotted switch.

Heretofore the allotment of a second switch has awaited the movement of the one previously allotted (the allotter being under the control of the latter, whereby a certain amount of time was lost in placing the former in condition for service). In the present invention th s-loss of time obviated by putting the allotter under control of the same means which controls the previously allotted switch, so that by the time this previously allotted switch has actually started to move, a new switch has been allotted.

In the drawings, Figure 1 represents diagrammatically a telephone substation and its associated central otlice apparatus, and Fig. 2 above the horizontal broken line represents diagrammatically three panel type line finders, and below the broken line three rclavs and a sequence switch COYHPIiSlIlg the allotter are shown.

In the operation of a system in which this improvement is employed, a group of lines are served by a number of line finders. of which one is allotted and ready togo into service, another is preselected for allotment, while others are in service. and still others are idle. When a call is initiated, a common start wire is grounded, whereupon an 18- position sequence switch associated with the allotted switch is caused to move forward to start an idle switch in motion. The movement of this sequence switch at the same time produces circuit changes in the allotter, which result in the advance of the preselected switch to the allotted position and th e,prese lectionoi' another idle switch.

The invention has been shown in connection with a part of a telephone system comprising a calling line, and three line finders available for extending a call.

it is thought that the invention ill best beunderstood from the following detailed description.

Referring now especially to Fig. 1, S represents a telephone substation, LR the line relay, and CO the cut-off relay associated therewith. Relay 1 and relay 2 are provided to serve the group of lines in which the calling line from substation Sis inchided. Relay 3 is common to a number of groups of relays similar to land 2.

When a call is initiated at the substation S, through the removal of the receiver from its hook, a circuit is esablished from ground, battery, winding of line relav LR, inner armature and contact of cut-oft relay C6 to the upper limb of the line leading to the substation S, through the apparatus comprising the substation. back through the lower limb of the telephone line, outer contact and armature of cut-oft relay CO to ground. The armatures of line relay LR are thereby attracted, whereupon circuit is established from ground, left-hand armature and contact of relay LE to the contact and armature of relay 1, through the winding of re lay 2, normal contacts of the right-hand armature of relay 2, contact and left-hand armature of relay 3 to battery and thence to ground. Relay 2 is energized in this circuit and attracts its armatures. Thereupon a circuit is established from ground, battery, through the winding of relay 3, through the left-hand alternate contact and armature of relay 2, the Winding of relay 2, the armature and contact of relay 1 through the left-hand armature and contact of relay LE. to ground, whereby relay 2 is locked up and the relay 3 is energized. The action of the relays associated with the substation S just described now results in the movement of a'line finder. A circuit is set up from ground, battery, winding of relay 3, alternate contact and left-hand armature of relay 2, alternate contact and ri ht-hand armature of relay 2. conductor TlV, to a trip magnet TM and thence to ground. This trip magnet attracts its armature and rotates the common trip rod TR, serving allline finders connected with the tilt) group of lines, in which the calling line is included. At the same time, a circuit is set up from ground, right-hand armature and contact of relay 3 to the common start wire SlV.

Assuming that position 1 of the sequence switch, such as sequence switch 100, serving a line finder is the allotted position and that line finder LF is in this position. The ground connected with the'start wire SlV is connected through sequence switch contact 101 to the winding of relay 120 to battery and thence to ground Relay 120 attracts its armaturesand a circuit is established from ground, right-hand armature and alternate contact ofrelay 120 through the sequence switch contact 102, the motor magnet of sequence switch 100 to battery and thence to ground. Sequence switch 100 mores undercontrol of its contact A. into position 3.

Let us assume that line finder LF" is in a preselected position in which case its sequence switch 200 will be found in position 16. As sequence switch 100 moves out of position 1 and passes through position 2, a circuit is established from ground, sequence switch contact 103 to the winding of relay 4 to battery and thence to ground. Relay 4 attracts its armature and establishes a locking circuit for itself from ground,

battery, winding 01' relay 4, contact and left-hand armature of relay 4, normal contact and right-hand armature of relay 5 to ground. Relay 1 in attracting its armatures establishes a circuit from ground, righthand armature and contact of relay l sequence switch contact 51, sequence switch contact 205 to the motor magnet of sequence switch 200, battery and thence to ground. Sequence switch 200 moves under control of its contact A into position 1, and is thereby allotted for service with the next calling line. i

As sequence switch 200 moves into position 16-}, a circuit is established from ground, battery, sequence switch contact 206, conductor 150, winding or" relay 5 and thence to ground, whereupon relay 5 attracts its armatures, thereby breaking the locking circuit of the relay 4 which retracts its armatures. Relay 5 establishes a locking circuit for itself from ground, battery, left-hand armature and contact of relay 6, left-hand armature and contact of relay 5, through the winding of relay 5 to ground. Relay 5 also establishes a circuit from ground, right-hand armature and alternate contact of relay 5, right-hand armatureand contact of relay 6, motor magnet of sequence switch 50, battery, and thence to ground. Sequence switch 50 now rotates its contactors until stopped in its movement by the preselection of an .idle switch.

Suppose now that line finder L1? is in use, line finder LF is allottechand that line finder LF is idle. In the idle position of line finder LF the sequence switch 300 will be resting in position lat. Then, as sequence switch 50 vbegins to move, in passing into position 25%, a circuit will be established from ground, sequence switch contact 803, sequence switch contact 52, winding of relay 6, contact and left-hand armature of relay 5, contact and letthand armature of relay 6, to batteryand thence to ground. Relay 6 is energized and attracts its armatures. Thereupon the locking circuit for relay 5 is broken and it retracts its armatures. This serves in turn to break, at the right-hand armature and alternate contact of relay 5 the energizing circuit for the motor magnet of sequence switch 50 whichcomes to rest in position 3. The allotter comprising the relays 1, 5 and 6 and the sequence switch 50 now rest in normal positio It will be seen then that the grounding of the start wire SW has the effect of instantly allotting a new line finder for service, and preselecting another for allotment.

When sequence switch 100 reached position 3 a circuit was established from ground, the right-hand armatureand alternate contact of relay 120, sequence switchcontact 107, the up-drive magnet 121 to battery and thence to ground. Magnet 121 attracts its armature and thereby presses the driving ribbon DR the constantly rotating roller 122. As the line finder switch moves in an upward direction, the pawlP' engages the catch C socured to the common trip rod TR and reof the line finder LF 'againstr leases the brushes B B 13 and B in the well-known manner. As the sequenceswitch 100 passed out of position 1 into position 3 the. relay 120 was maintained energized through a circuit from ground, battery, the winding of relay 120, the contact and lef hand armature of relay 120, sequence switch contacts 108 and 109 to the commutator segment US, the brush B and, thence to ground. In the upward movement of the line finder brush set, the brush B is ar- Relay 1 will be energized in this circuit andthereby open the holding circuit of relay 2.-' Relay 1 being slow to release will then hold its armature attracted. until the Should the first terminal be not one of a calling I lay 120 establishes a circuit cut-01f relay CO is energized as explained later. Relay 2 now ret acts its armatures, resulting both in the de'energization of relay 3-whereby the ground is removed from the start wire SlV and the releaseof the trip magnet TM.

When at last the terminals of the calling line are encountered, the test terminal'T will be in a changed electrical condition, that is, battery will be connected thereto through the circuit from ground, battery, right-hand winding of relay 1, alternate contact and right-hand armature of relay LR to the terminal T therefore relay 120 will be deenergized and the circuit for up-drive magnet 121 will be broken at the alternate contact and right-hand armature of relay 120.

The retraction oi its armature by relay from ground, righthand armature and normal contact of relay 120, the sequence switch contact 110 to the motor magnet of sequence switch 100 to battery and thence to ground. Sequence switch 100 moves under control of its contact A. into position 12.

lVhen position 4 is reached by sequence switch 100, a circuit is established from ground, battery, resistance R, sequence switch contact 111, brush B terminal T the winding of cut-off relay CO and thence to ground. The cut-01f relay CO attracts its armatures, thereby breaking the energizing circuit for the line relay LR, which in turn retracts its armatures.

As sequence switch 100 continues in its movement toward position 12, the sequence switch contacts 112 and 113 are closed in position 10%- and remain closed until position 12 is reached where the sequence switch comes to rest. Thus the substation S is extended through the terminals T and T the brushes B and B the sequence switch contacts 112 and 113, through the windings of repeating coil BC of the cord circuit connected with line finder LF'.

As position 10!,- is passed, a current flow is established through the said circuit including the winding of supervisory relay 123, which is thereby energized. Supervisory relay 123, in attracting its armature, establishes a circuit from ground, armature and contact of relay 123, the winding of re- 120 to battery and thence to ground. Relay 120 attracts its armature and remains in this condition until the conversation over the telephone line is concluded, at which time the circuit just described is broken. Thereupon the return of the right-hand armature ot-relay 120 to its normal contact establishes a circuit from ground, through the armature and normal contact of relay 120. sequence switch contact 110, in the twelfth position, the winding of the motor.,magnet of sequence switch 100 to batfi me tery and thence to ground. Sequence switch 1.00 moves under control of its contact A into its thirteenth position.

In position 13 sequence switch contact 114 is closed, thereby establishing a circuit for the down-drive magnet 124 from ground, battery, the winding of magnet 124, sequence switch contact 114 to ground. Magnet 124, in attracting its armature, presses the driving ribbon DR against the constantly rotating roller 125, whereby the brushes B, B 13 and B are returned to their normal position. As the normal position is reached, a circuit is established from ground, brush B, commutator segment 126, sequence switch contact 115, motor magnet of sequence switch 100 to battery and thence to ground. Sequence switch 100 moves under control of its contact A into position 14, where it remains idle until again preselected tor allotment, as described in connection with line finder L1 When another call is initiated start wire Pa /V will be grounded, as before described, and in this case line finder LF will go into service. Line finder Ll? which was preselected will thcreupon be advanced to the allotted position, and a new idle line finder such as LF will now be preselected.

What is claimed is:

1. In a telephone exchange system, a group of telephone lines, a plurality of automatic switches in which said lines terminate for extending said lines, means individual to each switch for controlling said automatic switches, and an allotter for determining the order in which said switches shall be operated, said allotter comprising means for selecting a switch for service and means for preselecting a second switch for service, said allotter being controlled by the controlling means associated with the last of said switches to go into service.

2. In a telephone exchange system,a group of telephone lines, a plurality of automatic switches in which said lines terminate for extending said lines, means including sequence switches, one for each switch for controlling said automatic switches, means for selecting an idle automatic switch for allotment, and means for allotting a selected automatic switch r'or service in connection with the next line to be extended. said last mentioned means being controlled by the sequence switch associated with the last automatic switch to go into service.

3. In a telephone exchange system,a group of lines, a plurality of automatic switches in which said lines terminate for extending said lines, means including a sequence switch individual to each automatic switch for controlling said automatic switches, an allotter associated with said switches for determining the order in which they shall be operated, comprising means for selecting an switch individual to each,

idle switch, and means for placing in readiof telephone lines, a plurality of automatic switches in which said lines terminate for extending said lines, means for controlling said automatic switches including a sequence and an allotter for determining the order in which said switches shall be operated comprising means for preselecting an idle switch, means for'allotting a preselected switch, said means being under control of the sequence switch associated with the last previously allotted automatic switch.

5. In a telephone exchange system, a group of telephone lines, a plurality of automatic switches in which said lines terinlnate tor extending said lines, a controlling means for each of said automatic switches, and an al-,v

lotter for selecting and preselecting said switches for service comprising means made operative when av selected switch goes into service for advancing the pre-selected switch to the selected position, said means being under control of the means for controlling the last previously selected switch, and means made operative when the preselected switch is advanced tothe selected for preselecting an idle switch. I

In witness whereof I hereunto subscribe my name this 11th day of N ovember, A, D. 1916.

FRANK N. REEVES.

tCopies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

' Washington, D. G.

position 

